Method for minimizing polymerization



2t' 'processingisteps, much "loss of Lde'sire'd products coholbeing'u's'edfor 'eachmol'e' of alkylh'ydr'ogenV Patented July 2 3, 1935 r y 2,000,062

. i 1,1. Y' fresa sVA UBHIEB vSTAFI'JEI PATENT .v QFFFICE :milanese Y f t f V4imi'lrHoDFOR mNIMIzING `PoIrinvIERIzA'rloN ,grenneunllaynnighlanafrark, Iu.,-ffessign0mo Nan SchaackyqBi-os, Chemical iWorks, -Inc., `Chicago,,Ill.,;acorporation of Illinois n i-No-Drawing. "'Ap'plicationApril-21, 1933;

, vSeil-No. 667,232 i f Y 16 claims. wieso-9942) d. Thisiinverrtionirlatestoa'lprocessorabsorbf notin'excesfs'.y of about v30"*0; `When sufficient" ng.ole'nes in Lsulfuric Lacid fand amethod `'for olene hasbeen absorbed to'complete-the-freaction minimizing the polymerization of the oleiir'ies of "Equationv (l'lfthatis, Awhen the sulfuric acid Whicheommonlyfccoursiniconrectionfwithcsuch has been Wholly or in majorpart conyertedto cklosorp'tion.V More particularly, it relates-'to the` alkyl 'hydrogen sulfateycontact between thejacid4 i5.

tseatmnteof-acid solutions'oftilkylhydrogen-sul;y liquor'(comprisingjwater, unreacted si'il'furioacid' fates With'aprimary ialcohol jin order toprevent and alkyl hydrogen sulfate, with lpossiblyl small` to a considerable extent *the forrnationof-poly-i vamounts ofi dialkyl sulfate, suspended: polymers, mers Which'takes'place,:otherwisefwith'thepasand other's'ubstancs) 'and the oleini'Qrriaterialisll) f sageoftime. g j stopped, An oil "layer containing: polymers fand 10 EW'hen clenesotherthan ethylene are absorbed anyum'eacted oleiines risesI to'the surface and n sulfuric acid, "for Iexample "as .a step iin'the may be removed. .Using thejmixturefof olenes" manufacture of secondary alcoholsbr otherprodbOV AdeSClbd and '75%` SuIfuIC acid, the leucts, -a 'portion Yof th'e olefnes Lformjplymeriz'ed quired degreel'of saturation will bej'reached'when 1115"? .products jwlch areinsolliblein'the liquid mena 'sample of acid'liquor from which polyn'lerslllave 15 struum. "The proportion .of olenes'-polymerized beena-llowedto,separate by gravitfyforabout aj andthe'speedwithwhich'thisoccurs Will depend4 half-lhoilrhas aspecic gravity in'the neighboron the-concentration fof theac'id, 'the"tem,pera hooddf 1;3. 1 v 0 turefthe degree rof "saturation "and other*factors; When the freactionfjhas ibe'e'n'f' 'carried ftojthe 20'Y But if a .sulfuric acid solution Yof, olenes be 'alpoint indicated', the `remaining reactivity of Athe' 30 lowedto'stand, even 'at Vortlinary room 'temperaac'idis lsatifsledwith ethyl alcohol;v The quantity tures, the 'amount lof polymers present Willinof alcohol addedy is Vstoichiornetrically propor# crease continuouslyo'rialongtiine, Sincemoe tioned to the remaining combining'capac'ityof or lessdel'ay is frequently unavoidable -between the Su1furic. a ci d, substantially one mole o'f alresults. c sulfate. 'If 'the absorption'of olenshasbee'n :time foundfthatjby the'suitableiimitauonnr stopped While there 'iS'eSbill uureeeiied sulfuricV thedegree or saturation ofthe'suuricLadwith acid present, two melee Ofelhel are required the olenes, together with thepromDt'additinnf OLeaGhi-nole of such unreacted acid. 'With ex- :m'f a iprimznty valcohol to complete the saturation of perieuee'iheameunt O'f a1eehe1,uece'ssay maybe 3o tnefaeid,,polymerizationinaddition to thatwhich determined Sfrom the Specific gravity of the acid Has lready voccurred-Qliiri'r'igthe b'sorfitiommay Aliqluorfarld this Will varyaccordingtofth'e initial be' or even practically iinnibited,.and eneeutratien-Of 4.the acidzahdtheprticuljar ele-` ihe aialiqiiormy when be .stored witnoutsubues employed The "amount muy aise be ce1#` until 'itcanbgmheI-pregsd pu't'ation, 1after titration of a sampleof 'the'ac'id fj'he jrocgss' win bedescnbedstjmayab@ aps liquor withstandard alkali solution; The alcohol plied the .absorbnon ofthe normally liquid iSlWeil mixed 'with `the acid liquor, preferably fractions -,of ,1i/'3,1501'--plaseV .cracked @petrolem with cooling .to/ maintain the temperature asbe- 'ne'stsodenwed suchrffbtions @mist mainly until .it is convenient to processlitfv'iuither Acid df the-'series of `oleiines ffrmthe .butenesft'o `the 121,@1101 'Ifiluleland treated as ldesCllfilfdfis llSell'y heptene's, with 'smaller quantities of higher 01e'- fer the .Preparation ef Seeeudery leehe'ls' .upe'n fines and .Withisomelofthe lowerblenes `present dilution ad distuafoh'by kownllethdsthe 45asss1dg'ses; .Thegentenesaizelypcalcmethyl elcohol being separated by 'fractionation 45.f

stiguetsof Simhmenemixtmfe' Thyaybe Or esters or ethers may be made from the acid conceived ,to react fyvit'h suIfur'icinltwoisteps: liquorl j y Contact between the sulfurlc acldand olenes y "(IfGHrn-{fI-IQSQwGHiHSOi .in the first step of the process may be brought 501i' (2j) GHmvkCsHnHso@511113)2'SO' c about in any of the Ways Well known in the 5o? ant. Forfexamplegfif :the koleiinejsiinathefliquid-' Suita'llytherriikturefd-olenesiis contacteliti# phase','tit=`=.may :be aagitated WithA the acid .inaaVv mately ffwlthidilute Lsulfuric -acid`o eafconcentifaolosedzvessel'..` @rthe'two liquidsrmaybepumped tion of 95% iby Weig'htpwithsuch cooling as :may into and :through a-common .pipeii "sfzthe olenes 56 `beTuiredltornaintina'temperature preierlly are :in the gas 'nhase; "they may. 'abe :'bubbled;

pressures may be treated, or in the case of ole` fines normally liquid, the temperature of the absorption may be such as to maintain them in the gaseous state. On the other hand, some olefines which are normally gaseous rmay be treated in the liquid phase by maintaining the apparatus under suitable pressure. The concentration of sulfuric acid used may be varied, depending in part on the particular olenes being treatedv and the temperature at which the reaction is carried out. Acid from 65% to 98% is suitable according tothe circumstances. The temperature may in some instances be allowed to go higherthan 30, or a maximum lower than this may be desirable. In general, the lower the concentration of the acid within the limits described, the higher the temperature which may safely be employed. Olenes with a smaller number of carbon atomsv may be absorbed in more concentrated acid and at a higher temperature than those with a larger number of carbon atoms, though the configuration of the oleflne molecule is also a factor.

When ethyl alcohol is used, it may conveniently' be in the form of the commercial product which contains about 94% of the alcohol by weight,

but the use of alcohol of other concentrations,

preferably over 50%, is not precluded. Someof the various forms of denatured ethyl alcohol may v The process results in the formation of dialkylv derivatives of sulfuric acid, one of the hydrogen atoms of the acid being replaced by a secondary alkyl group, derived from the olefine or olenes, such as isopropyl, sec-butyl and the like. The other hydrogen atom of the acid is replaced by a primary alkyl group derived from the primary alcohol which was employed. Thus acid liquors which have been treated with one or more primary alcohols in accordance with this invention may comprise such compounds as ethyl secamyl sulfate, ethyl isopropyl sulfate, n-butyl secbutyl sulfate, isoamyl secbutyl sulfate, and the like, or mixtures thereof, which may be in solution in excess sulfuric acid and water. Such compounds have the general formula SO i 4\ /R CH R2V Where R represents the radical of a primary alcohol, and R1 and R2 represent alkyl groups. They usually cannot be distilled Without decom position. They are heavier than Waterbut upon treatment therewith, particularly at elevated temperatures, are decomposed either into the corresponding primary and secondary alcohols; or, by adjusting acid concentrations and temperatures, primary, secondary and/or mixed ethers are formed.

What I claim is:

l. Aprocess which comprises reacting sulfuric acid partially with an olene higher" than ethylene, and thereafter adding a primary alcohol'in an amount sufficient to satisfy the remaining reactivity of the sulfuric acid.

2. A process 'which comprises reacting sulfuric acid partially with a normally liquid olene, and thereafter adding a primary alcohol in an amount sufficient to satisfy the remaining reactivity of the sulfuric acid.

3. A process which comprises reacting sulfuric acid partially with a hydrocarbon mixture comprising in substantial amount the series of olenes from butenes to heptenes, and thereafter adding a primary alcohol in an amount sufficient to satisfy the remaining reactivity of the sulfuric acid.

4. A process which comprises reacting sul- `acid partially with a hydrocarbon mixture comprising in substantial amount the series of olenes from' butenes to heptenes, and thereafter adding ethyl alcohol in an amount suflcient to satisfy the remaining reactivity of vthe sulfuric acid. Y

' 7. A process which comprises contacting sul-` furic acid with an olene higher than ethylene whereby alkyl hydrogen sulfateis formed, discontinuing the contacting at a Vpredetermined concentration of said alkylhy'olrogen sulfate, before any substantial amount of dialkyl 'sulfate is formed, and relativelyr soon thereafter adding sufficient ethyl' alcohol to the mixture to satisfy stoichiometrically the lremaining 'combining capacity of the sulfuric acid. l y

8. Aprocess which comprises contacting sulfuric acid with successive portions of 'olefine higher than ethylene, said portions optionally having been first contacted with other vportions of sulfuric acid, whereby a part at vleast of said sulfuric acid is converted into alkyl hydrogen sul-A fate, removing the ac idliquor from further con-v tact with olene at such a concentration of alkyl hydrogen sulfate that substantiallyV no dialkyl sulfate is formed, yand relatively soon thereafter adding a suflicientamount of ethyl alcohol to the acid liquor to -satisfy stoichiometrically ,the remainingA combiningv capacity vof the sulfuric acid. 1

9. lA process' which comprises contactingsulfuric acid with successive portions Vof -oleflheY higher than ethylene, vsaid portions `optionally having been first contacted with' other portions of sulfuric acid countercurrently, whereby a part at least of said sulfuric acid is converted into alkyl hydrogen sulfate, removing'the acid` liquor from further contact with olene at such a'concentra-lv tion of alkyl hydrogensulfate Ythat substantially no dialkyl sulfate is formed, andrelatively soon thereafter adding a suflicient amount of ethyl-- alcohol to the acid liquor to satisfy stoichiometrically the remaining combining capacity of the sulfuric acid.

10. A process which comprises contacting sulfurie acid with successive portions of olene higher than ethylene, said portions optionally having been first contacted with other portions of sulfuric acid, whereby a part at least; of said sulfuric acid is converted into alkyl hydrogen sulfate, removing the acid liquor from further contact with olefine at such a concentration of alkyl hydrogen sulfate that substantially no dialkyl sulfate is formed, and relatively soon thereafter adding a, sufficient amount of a primary alcohol to the acid liquor to satisfy stoichiometrically the remaining combining capacity of the sulfuric acid.

11. A process which comprises contacting sulfuric acid with successive portions of olefine higher than ethylene, said portions optionally having been first contacted with other portions of sulfuric acid, whereby a part at least of said sulfuric acid is converted into alkyl hydrogen sulfate, removing the acid liquor from further contact with olene at such a concentration of alkyl hydrogen sulfate that substantially no dialkyl sulfate is formed, and relatively soon thereafter adding a suicient amount of a liquid primary alcohol to the acid liquor to satisfy stoichiometricallythe remaining combining capacity of theV sulfuric acid.

l2. A process which comprises contacting sulfuric acid of not substantially lower concentration than '75% with an olene higher than ethylene whereby alkyl hydrogen sulfate is formed, discontinuing the contacting at a predetermined concentration of said alkyl hydrogen sulfate, be-

fore any substantial amount of dialkyl sulfateVV is formed, and relatively soon thereafter adding sufficientV ethyl alcohol to the mixture to satisfy stoichiometrically the remaining combining capacity of the sulfuric acid.

13. A process which comprises contacting sulfuric acid of not substantially lower concentration than 7 5% with successive' portions of olefine higher than ethylene, said portions optionally having been first contacted with other portions of sulfuric acid, whereby a part at least of said sulfuric acid is converted into alkyl hydrogen sulfate, removing the acid liquor from further-contact with olene at such a concentration of alkyl hydrogen sulfate that substantially no dialkyl sulfate is formed, and relatively soon thereafter adding a sufficient amount of ethyl alcohol to the acid liquor to satisfy stoichiometrically the remaining combining capacity of the sulfuric acid.

14. A process which comprises contacting sulfuric acid of not substantially lower concentration than with successive portions of olefine higher than ethylene, said portions optionally having been rst contacted with other portions of sulfuric acid, whereby a part at least of said sulfuric acid is converted into alkyl hydrogen sulfate, removing the acid liquor from further contact with olefine at such a concentration of alkyl hydrogen sulfate that substantially no dialkyl sulfate is formed, and relatively soon thereafter adding a suflicient amount of a primary alcohol to the acidA liquor to satisfy stoichiometrically the remaining combining capacity of the sulfuric acid.

15. A process which comprises contacting sulfuric acid with an olene higher than ethylene in liquid phase whereby alkyl hydrogen sulfate is formed, discontinuing the contacting at a predetermined concentration of said alkyl hydrogen sulfate, before any substantial amount of dialkyl sulfate is formed, and relatively soon rthereafter adding sufficient ethyl Valcohol to the mixture to satisfy stoichiometrically the remaining combining capacity of the sulfuric acid. Y

16. A process which comprises .contacting sulfuric acid with successive portions of olefine higher than ethylene in liquid phase, said portions optionally having been first contacted with other portions of sulfuric acid, whereby a part at least of said sulfuric acid is converted into alkyl hydrogen sulfate,lremoving the acid liquor from further contact with olene at such a concentration of alkyl hydrogen sulfate that substantially nodialkyl sulfate is formed, and relatively soon thereafter adding a suflicient amount of a primary alcohol to the acid liquor to satisfy stoichiometrically the remaining combining capacity of the sulfuric acid.

KENNETH B. LACY. 

